Cut-off-valve gear



2 ShBGtS ShBGt 1. J. W. McPAR-LAND.

GUT-OFF VALVE GEAR.

(Model.)

No. 310,903.- Patented Jan. 20, 1885.

2 Sheets-Sheet 2.

(Model) J. W. MQFARLAND.

GUT-OFF VALVE GEAR.

No. 310,908. Patented Jan. 20,1885.

'Wfiraess es fr /gft w UNiTnn STATns PATENT FFTCEQ JOHN XV. MOFARLAND, OF ALLIANCE, OHIO.

CUT-OFF-=VAL.V'E GEAR.

EPECIFICATION forming part of Letters Patent No. 310,903, dated January 20, 1885.

Application filed January 5, 1884. (Model) T0 60% whom it may concern:

Be it known that I, JOHN W. DIOFARLAND, a citizen of the United States, residing at Alliance, in the county of Stark and State of Ohio, have invented a new and useful Improvement in Automatic Out-Oif-Valve Gear for Steam-Engines, of which the following is a specification.

My invention relates to certain improve ments in automatic cut-offs,by which the cen- -trifugal force of revolving weighted arms acts upon an inside eccentric in such manner that the motion of the outside eccentric by which the cut-off is actuated is shortened or lengthened, and by this means the speed of the engine is regulated.

In reference to the accompanying drawings, Figure 1 is a front elevation showing the position of the two eccentrics, with their rela tion to each other, and the dotted lines of which show the change which takes place in the outside eccentric by means of the change of the position of the inside eccentric. Fig. 2 is a longitudinal sectional view of Fig. 1, and Fig. 3 is a View showing the disk to which the weighted arms are attached; also showing the weighted arms, the eccentrics, and their connections.

B is a large disk, upon which the arms r s are pivoted, and with which the springs j k are attached. The said disk is also firmly connected with the shaft h and revolves with the said shaft.

a is the outside eccentric, (surrounded by the yoke 1a,) and which contains an orifice which is filled by the eccentric'b. The office of the said eccentric bis to shorten and lengthen the throw of the'outer eccentric by chang ing it from its greatest eccentricity to a position more nearly concentric with the shaft. The yoke at has a rod connecting it with the valve of the engine. The valve is operated by the motion of the eccentric a. j and 7c are springs, the office of which is to draw the arms r and s, with their weights d and e, toward the center, and thus operate against the centrifugal force which tends to throw them outward.

u is a feather which is firmly fastened in the shaft h, and passes through the eccentric b at its thinnest portion, outward and into the outer eccentric a, and is curved, as shown in Fig. 1, to permit it to move partly out of the eccentric a.

w is an arm which extends from the outer eccentric, connected with one end of which is one end of the spring 0, and the other end of said spring 0 is connected with the pro jection w. The use of said devices to, 0, and a; is to hold the eccentric a against the said feather u in such manner as to take up any lost motion in said eccentric a and hold it firmly in position. The dark mark 12 shows where the inner eccentric, b, is cut away to such extent as to allow the said eccentric to revolve a sufficient distance.

The operation of my invention may be described as follows: VVhen the engine is set in motion, the shaft 71, which is connected with the piston-rod of the engine, is caused to revolve, and carries with it the disk B, and therewith all the improved parts of the invention, and as the said disk and parts revolve the centrifugal force produced thereby causes the weights d and e to move in an outward direction, and thereby revolves the i11- ner eccentric, b, in the direction indicated by the arrows, and as the said-eccentric b revolves upon the shaft h it causes the eccentric a to change from its eccentric position and to assume a position which causes the shaft h to be nearer the center of the eccentric a, t

and by this means shortening the stroke of the valve-rod e. As the speed of the said disk, with its parts, slackens, the arms r and s, with their weights (1 and e, assume a position nearer the center of said disk B, and the eccentric to again resumes its original stroke. The dark part 21 shows a recess in the eccentric b,which determines the limit of the motion of the inner eccentric.

The object of the feather a is to make a rigid driver for the eccentric a, and the incline on the same is for the purpose of turning said eccentric a forward to equalize the point of letting on steam after the stroke has been shortened.

WVhat I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination of the eccentric b, hav- IOO ing the cavity 11, the feather u, and the eccentric a, the eccentric I) being set inside of and at right angles with the eccentric a.

2. The combination of the eccentrics a and b, the shaft h, and the feather u, with its incline or curve, as shown.

3. The combination of the eccentric a,with its arm w, the spring 0, feather u, and the pro jection to which the spring 0 is attached.

4. The combination, with a shaft, of an inner and outer eccentric, the outer eccentric being loosely keyed to the shaft, substantially as and for the purpose set forth.

5. The combination, with a shaft, ofan outer and inner eccentric, said outer eccentric being loosely keyed to the shaft, and a governor upon the said shaft for automatically shifting JOSHUA H. Woons, SAML. V. ESSIOK.

the eccentrics, substantially as and. for the 

